Which PBMs Have The Highest Mail Order Penetration?

I was looking at some data from earlier this year (Q1 – 2011) from the AIS quarterly survey of PBMs. I thought this was a nice summary of mail order penetration by PBM. As you can see, it identifies some areas of opportunity:

Will Express Scripts’ mail penetration go up with the potential acquisition of Medco? Or, will Medco’s go down?